Conventionally, chain conveyors or the so-called "walking beams" are used for conveying metal coils.
The former is driven by chains. Consequently, its accuracy of positioning is substantially influenced by elongation of the chains. Thus, a separate positioning device is required between the carriages and the automatons.
In case of the latter, metal coils are conveyed while lifting and lowering the metal coils. Therefore, it is liable to cause damage to the metal coils, and is not preferable from the viewpoint of maintaining the quality of the finished products.
Also, both types of conventional equipment require various apparatus under the conveying path of the metal coils. Namely, in case of a chain conveyor, vertically and endlessly circulating chains and their driving devices are needed. And in case of the walking beams, their driving apparatus and hydraulic apparatus for advancing metal coils are required. Thus, the conveying level of the metal coils is inevitably relatively high and the total cost for installation is also high.
One solution for lowering the conveying level of the metal coils is to provide a pit under the floor, but it has a drawback that the cost therefor is also high.
The objects of the present invention are firstly to provide a conveyor of high positioning accuracy; and secondly to provide a conveyor which is capable of conveying articles with a relatively simple structure while causing little damage to the articles; and thirdly to provide a conveyor of a lower conveying level.